1. Field of the Invention
This invention relates generally to telephone equipment and more specifically to a structure and method for retrofit of a pay telephone for use by inmates or in other environments wherein the telephone is subject to abuse (hereinafter referred to as a safety phone).
2. Description of the Related Art
Numerous hands-free telephone equipment systems have been taught in prior art. U.S. Pat. No. 2,277,907, issued to Goodale, Jr. et al., discloses a speaker attachment for a conventional telephone. U.S. Pat. No. 3,144,513, issued to Sherron, teaches a partially enclosed telephone stall with a microphone and speaker mounted in the enclosure wall of the booth. U.S. Pat. No. 4,101,735, issued to Bridenbaugh, uses a shared transducer, alternately functioning as a speaker and a microphone, connected to a conventional telephone. U.S. Pat. No. 4,104,485, issued to Pessel et at, discloses a loudspeaker system mounted over a conventional telephone. U.S. Pat. No. 5,371,790, issued to Nevo et at, discloses a telephone such that a mouthpiece, an earpiece, an electronic circuit board, a push-button dialing pad and a dial tone actuating switch are contained in a single housing and which places the entire phone in a housing similar to a conventional telephone handset. The Nevo '790 patent does not teach safety and vandal resistance elements; in fact, the entire phone or alternatively the exterior connection cable may easily be used as a weapon. None of the prior art utilizes a design for a telephone that can be securely mounted to a wall or other support structure, and is self-contained with minimal external parts, as described herein.